The invention achieves giving high color reproducibility to a color signal with reliability without substantially increasing circuit scale. A signal processing unit of the invention includes a color transformation part which multiplies an inputted color signal by a transformation matrix and an element setting part setting an element group of the transformation matrix according to every inputted color signal. The element setting part comprises an identification unit identifying a color of the color signal, a storage unit storing in advance optimum element groups for a predetermined number of reference signals, and an interpolation unit. The interpolation unit performs interpolation computing based on the input signal, two optimum element groups for two of the reference signals of colors close to a color of the color signal, and color relation between the color signal and the two reference signals to determine an element group to be set.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A signal processing unit comprising: a color transformation part for performing color transformation processing on an inputted color signal having plural components by multiplying the color signal by a transformation matrix; and an element setting part setting, every time a color signal is inputted, an element group of the transformation matrix to be used for the inputted color signal according to a hue of the inputted color signal, wherein said element setting part composes: an identification unit for identifying quadrant information indicating a quadrant to which the hue of the inputted color signal belongs and angle information indicating an angle within the quadrant of the hue; a storage unit storing in advance an optimum element group for each of a predetermined number of reference hue signals; and an interpolation unit for recognizing two pairs of optimum element groups for two of the reference hue signals close to the hue of the inputted color signal, in reference with said storage unit according to the quadrant information and the angle information, for performing interpolation computing with the two pairs of the recognized optimum element groups after performing weighting according to the angle information to the two pairs of optimum element groups, and for determining the element group to be set according to the hue of the color signal.
2. The signal processing unit according to claim 1 , wherein: said storage unit has a lookup table; and an argument of the lookup table represents a color range to which the hue of the color signal belongs, and a function of the lookup table represents two pairs of optimum element groups for the two of reference hue signals located on borders of the color range.
3. The signal processing unit according to claim 1 , wherein said element setting part arranges the predetermined number of reference hue signals with uneven intervals in a hue space.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
September 13, 2002
September 8, 2009
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